On June 13, 1980, a young Jason Voorhees watches as his mother Pamela is beheaded by a camp counselor, who was trying to escape Mrs. Voorhees's murder spree around Camp Crystal Lake. Almost thirty years later, a group of friends— including Whitney Miller —arrive for a camping trip at Crystal Lake, where they hope to find a crop of marijuana growing in the woods. That night, an adult Jason kills everyone except Whitney, whom he captures as she resembles his mother at a young age.
Six weeks later, Trent, his girlfriend Jenna and friends Chelsea, Bree, Chewie, Nolan, and Lawrence arrive at Trent's summer cabin on the shore of Crystal Lake. Meanwhile, Whitney's brother Clay Miller arrives at the lake to search for her. Clay visits Trent's cabin, and Jenna agrees to help him search for Whitney. Chelsea and Nolan go wakeboarding on the lake where Jason kills Nolan with an arrow, and fatally stabs Chelsea with a machete. Meanwhile, Clay and Jenna search the old Crystal Lake campgrounds, where they see Jason hauling a body into the abandoned camp house.
Jenna and Clay run back to the cabin to warn the others about Jason. Chewie is killed by Jason in a tool shed near the cabin, while Trent and Bree have sex in a bedroom. Jenna and Clay arrive, and Clay calls the police. Jason then disconnects the cabin's electricity. Lawrence heads outside to search for Chewie, and Jason kills him with an axe. Jason then sneaks inside and kills Bree. A police officer arrives and knocks on the front door, but is killed by Jason before he can enter. Trent, Clay, and Jenna escape the cabin and become separated, and Trent is killed by Jason when he reaches the main road.
Jason chases Clay and Jenna back to the campgrounds, where Clay discovers Jason's lair and finds his sister underground, chained to a wall. Clay frees Whitney, and all three try to escape as Jason arrives. They find an exit, but Jenna is killed before she can escape. Jason corners Clay and Whitney in a barn, and Whitney confuses Jason by pretending to be Pamela. Clay and Whitney subdue Jason with a length of chain, and Whitney stabs Jason in the chest with his own machete. After sunrise, Clay and Whitney dump Jason's body into the lake, but before they leave, Jason bursts through the wooden dock and grabs Whitney.